1. Field of the Invention
The present invention relates to semiconductor devices in general and more specifically to a memory card having a resin-molded layer without a plastic card base and a process for making memory cards.
2. Description of the Prior Art
A conventional memory card includes a card base made of plastic material. A molded package containing a semiconductor chip is inserted in and attached to the plastic card base. The package typically includes a printed circuit board having contact pads thereon. A circuit pattern in and on the circuit board electrically connects the contact pads to the chip mounted on the opposite side of the circuit board. The contact pads provide an electrical connection between the memory card and a card reader.
FIG. 1 shows an exploded perspective view of one example of a known memory card 10. In FIG. 1, the memory card 10 includes a plastic card base 13 into which a package 11 fits. An adhesive tape 12 attaches the package 11 to the card base 13. The card base 13 has two recessed areas 15 and 17 sized to receive the package 11. One recessed area 15 receives a resin-molded part 14 of the package 11, and the other recessed area 17 accepts a circuit board 16 and the adhesive tape 12.
Since the memory card 10 has two main members, namely, the package 11 and the card base 13, the process for manufacturing the memory card 10 requires two separate sub-processes that fabricate the respective members and a following sub-process to combine the package 11 and the card base 13. The number of processing steps makes this conventional process complicated. In addition, the process has significant drawbacks when producing the memory cards in large quantities because each package should be separately combined with the respective card base. Further, the requirement for multiple members (the card base, the package, and the adhesive tape) leads to higher manufacturing costs.
Memory cards have been widely used in electronic devices such as digital cameras, personal digital assistants, musical instruments, voice recorders, facsimile machines, printers, scanners, word processors, game machines, PC cards, and the like. The general trend in devices using the memory card is to make the devices smaller, lighter, thinner, more reliable, and less expensive. Meeting this trend requires smaller memory cards, but reducing the size of the memory cards is difficult because of the structural limitations that the card base imposes.